1. Field of the Invention
The present invention relates to whirlpool bath assemblies. In particular the invention relates to a whirlpool bath assembly comprising a pump recirculation unit, a suction system pipe having an inlet for mounting in a bath and outlet feeding the pump recirculation unit, a venturi jet unit having a water supply inlet, an air inlet and a combined air and water outlet, venturi mounting means for securing the venturi jet unit to a bath side wall, a system feed pipe between the pump recirculation outlet and the venturi, a drain-off valve connected to the pump a waste-water pipe fed from the drain-off valve and a control unit.
2. Background Information
Whirlpool systems have become increasingly popular and this has led to the retro-fitting of these into domestic baths and in baths of hotels or similar establishments. Typically these systems are made from a large number of components which, unless they are very carefully designed, could have numerous places where water will remain after cutting off the whirlpool and draining the bath. Many so-called self-draining systems are so made as to have a large number of pockets within which water can be retained. For example, water can be retained in bends in the system pipes, in the water recirculating pump, in the venturi jet units and indeed in all the components: very often the connection of one component to another forms a water retaining pocket or recess.
Heretofore such whirlpool baths or jacuzzis were effectively luxury items and little attention was paid to the design, or more particularly the technical aspects. This has led to whirlpool assemblies with a large number of parts and it is recognised that in any plumbing equipment the more parts that have to be joined together the more likely it is that there will be leaks in the system since each part joined together is a potential for a leak, no matter how good the sealing and fitting is.
For example, U.S. Pat. No. 4,358,862 (Altman et al) concentrates on the provision of better connections so that the air and water supply channels can be made from continuous tubing. This was one attempt to obviate the need for additional connections such as elbows and T-fittings which increases construction time and cost. A considerable amount of work has concentrated on the control aspects of the whirlpool bath such as described in U.S. Pat. No. 4,542,854 (Mathis). The same inventor is the patentee in respect of earlier improvements in the general construction of whirlpool jets as shown in U.S. Pat. No. 3,890,655 (Mathis). Again U.S. Pat. No. 4,408,721 (Cohen et al) is another attempt to improve what can be best described as the operational and technical efficiency of such whirlpool baths or jacuzzis. However, none of these specifications do more than tackle minor technical problems relating either to general plumbing arrangements, or to the actual efficiency of the units themselves.
A further problem with such whirlpool assemblies which has been recognised for a long time is the problem of hygiene and thus infection. Since by their very nature whirlpool baths utilise hot water, they are therefore warm and moist and provide a fertile breeding ground for disease causing organisms including Legionella bacteria which can cause the sometimes fatal Legionnaires disease and number of less dangerous though still serious diseases such as Pseudomonas which can cause severe skin rashes, ear infections and even pneumonia. In spite of claims that disinfectants can cure this and it has long been proposed by back-flushing with disinfectant, etc., they have heretofore proved to be relatively inefficient. Undoubtedly the use of disinfectants is to be applauded, however, by far the best way is prevention i.e. if the whirlpool assembly can be kept free of stagnant water and clean at all times, then the possibility of disease is greatly reduced.
There have been may so-called self-draining systems most of which do not work. What are often called self-draining Systems are those which retain somewhat of the order of 30 ml of water. One glass of water per system is common in most of the world as being acceptable and claims to less than this such as "an egg cup full" have appeared in sales literature. It is a long recognised problem with heretofore no solution and from the terminology used little scientific analysis. Such that the public will understand quantities of water even if the volume corresponding to such terms is indeterminate. One of the most important places to have the assembly self-draining is within the venturi jet unit itself. Indeed in European Patent Specification No. 0 445 504 (Ucosan BV) there is illustrated a venturi jet unit, which, if correctly assembled and made could be self-draining. It is partly self-draining, but is not self-draining for certain obvious reasons. Firstly, the water retained in the inlet pipes to this venturi jet unit would have to drain back to the pump. This would require that the venturi jet units be placed in a position higher than the top of the pump, which will negate the whole benefit of such a design as the objective is to get the venturi jets as low as possible within the bath to optimise the massaging effect of the venturi jet units. Indeed it has to be admitted that this venturi jet unit could be modified to provide a self-draining venturi jet unit, however, it is submitted that it is not envisaged by this patent specification. Essentially any self-draining venturi jet unit must be designed to accommodate the differing bath wall thicknesses and the varying slope of the bath. In any case the problem is not in the design of individual parts of a whirlpool assembly but in producing a composite assembly that is totally self-draining.